Neil deGrasse Tyson says this new video may contain the 'most important words' he's ever spoken

Richard Shotwell/Invision/AP The astrophysicist Neil deGrasse Tyson has released a video urging Americans to change how they relate to science.

Tyson posted the video on his Facebook page alongside this note:

"Dear Facebook Universe,

"I offer this four-minute video on 'Science in America' containing what may be the most important words I have ever spoken.

"As always, but especially these days, keep looking up."

Tyson's message in the video centers on what he sees as a worrisome decline in scientific literacy in the US.

"Science is a fundamental part of the country that we are," he says in the video. "But in this, the 21st century, when it comes time to make decisions about science, it seems that people have lost the ability to judge what is true and what is not."

That shift, he says, is a "recipe for the complete dismantling of our informed democracy."

Tyson's speech is interspersed with clips of political debates and news. The video cuts to a clip of Vice President Mike Pence, then a congressman speaking on the floor of the House of Representatives.

"Let us demand that educators around America teach evolution not as fact, but as theory," Pence says in the clip.

The role of science, Tyson says, is to provide the factual grounding for politics. The role of politics is to decide what to do about those facts.